Steam generating system



Feb. 13, 1934. FRENCH 1,946,682

STEAM GENERATING SYSTEM Filed June 15, 1933 Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE Claims.

This invention relates to a steam generating system. More specifically it relates to an improvement in boiler design of the semi-flash type.

The principal object of the invention is to pro- 5 vide in a boiler of the semi-flash type means for removing the major portion of water from the boiler to facilitate firing up of the boiler.

Other objects and the means by which they are attained will be apparent from the construction shown in the single figure of the drawing and in the detailed description to follow.

In the drawing a boiler casing is shown somewhat diagrammatically, in which preheating coils l1, vaporizing coils 12, and super-heating coils 13 are shown. A burner 14 is diagrammatically represented as positioned over one end of the casing 10.

From a hot well 15 containing water for the system water is drawn by a feed pump 16 through a conduit 17 and forced through a conduit 18 into the preheating coil 11. A check valve 19 positioned in the pipe 18 prevents the return of water to the feed pump.

The preheating coil 11 is connected by a pipe 20 with the bottom of a steam storage drum 21. The vaporizing coil 12 communicates with the bottom of the drum 21. A check valve 22 is positioned in said coil adjacent the outlet from said drum to prevent flow into the drum at that end of the vaporizing coil. The other end of the vaporizing coil communicates with the upper end of the drum 21 above the normal liquid level therein. The super-heating coil 13 communicates with the drum 21 above the normal liquid level therein and extends to a source of steam consumption, for example, the engine 23 diagrammatically illustrated. A throttle valve 24 regulates the amount of steam delivered to the engine. The engine 23 exhausts through a pipe 25 to a condenser 26. A pipe 27 from the condenser delivers into the hot well 15.

A conduit 28 communicates with the discharge end of the preheating coil 11 and with the inlet end of the vaporizing coil 12, terminating in a nozzle 29 directed into the direction of flow in said vaporizing coil. A check valve 30 is positioned in said pipe to prevent the flow of water back into the preheating coil. A check valve 31 is positioned in the pipe 20 to prevent the flow of water from the preheater coil into the drum,

permitting flow of water from the drum. A

casing 32 communicates through a pipe 33 with the vaporizer coil 12. A piston 34 mounted in said casing divides the casing into two chambers, the upper one of which communicates with the pipe 33. The lower chamber communicates through a pipe 35 with the preheater coil 11. A push rod 36 connects the piston with a plunger 3'1 mounted for reciprocation in the lower part of the casing 32. Said plunger is constructed to pass over a port in the casing 32 with which a pipe 38 communicates. The piston has an opening formed therethrough to equalize the pressureabove and below it.

A pipe 39 communicates with the lower chamo5 ber of the casing and with the feed water supply pipe 18. A spring 40 mounted in the upper chamber of the casing is positioned to exert pressure downwardly on the piston 34. The pipe 38 communicates with the hot well 15. It is provided 10 with a control valve 41.

In the normal operation of the boiler, as above described, the feed water pump 16 is practically continually returning condensate from the condenser hot well 15 through the preheating coil 11 and into the inlet end of the vaporizing coil 12. Some steam is made in the preheating coil. The mixture of steam and water passing through the forcing nozzle 29 entrains water from the drum 21, said water passing the check valve 22, and forces said water into and through the vaporizing coil 12. The preheating coil has its only connection with the boiler through the forcing nozzle 29 so that a higher pressure is carried in the coil than in the boiler, thus providing pressure to B5 operate the forcing nozzle or ejector.

In firing up the boiler as soon as the water contained in the upper part of the preheating coil 11 is made into steam and discharged through the ejector nozzle 29, the pressure in that coil and the evaporating coil 12 becomes nearly equal. As the evaporating coil 12 is connected to the upper chamber of the casing 32 through the pipe 33, pressure is exerted against the piston 34.

As pressure is transmitted throughthe pipe 35 to the lower chamber of the casing 32 the pressures on the two sides of the piston 34 are substantially the same. The spring 40 then forces the piston and the plunger 37 carried thereby downwardly, uncovering the port communicating with the pipe 38. This allows the water under pressure in the preheating coil to flow through the pipe 35, the lower chamber of the casing 32 and the pipe 38, out of the high pressure system into the hot well 15. Water then flows from the drum 21 past the check valve 31 into the preheating coil 11, which is closest to the fire. The flashing into steam of this water causes pressure to rise in the preheating coil, thus transmitting an increased pressure to the lower chamber of the oas- 11o ing 32 and raising the piston 34 against the spring 40, thereby closing the communication of the lower chamber with the drain pipe 38. The boiler then continues to operate in the conventional manner.

When the operation of the boiler is discontinued, the feed pump 16 no longer builds up pressure in the preheater coil. This allows the pressure to drop in the lower chamber of the casing 32, whereby the piston and plunger drop therein, opening communication between the lower chamber of the casing and the drain pipe 38. Water from the storage drum 21 is forced by the pressure remaining in the steam, out through the pipe 20, past the check valve 31, back through the preheater coil 11, and out through the pipes 35 and 38 to the hot well 15. When operation of the boiler is again initiated, the action as above described is again repeated.

It is to be understood that applicant has shown and described only one structure embodying the principles of his improved boiler control and regulation and that he,claims as his invention all modifications falling within the scope of the appended claims.

What is claimed is:

1. In a boiler of the semi-flash type the combination of a storage drum a preheater coil, means for forcing feed water through the preheater coil, a vaporizing coil connected at both ends to the storage drum, means for connecting the preheater coil to the vaporizing coil including an ejector, said ejector means operative to circulate water from the drum through the vaporizing coil, a water storage container, means for delivering water from the storage drum to the storage container, and means operable by pressure differential between the preheater coil and ,the vaporizing coil for controlling the how of water from the storage drum to the storage container.

2. In a boiler of the semi-flash type the combination of a storage drum, a preheater coil,

means for forcing water through the preheater coil, a vaporizing coil connected at both ends to the storage drum, means for connecting the preheater coil to the vaporizing coil, a connection between the preheater coil and the drum below the normal liquid level therein, a check valve positioned in said means for preventing the flow of water from the preheater coil into the drum, a water storage container, a fluid connection between the preheater coil and said container, and

a pressure regulating device in said connection,

said device having a connection to the vaporizing coil and containing means operable to control the flow of water to the storage container actuated by pressure difierential between the vaporizing coil and the preheater coil.

3. In a boiler of the semi-flash type the combination of a storage drum, a preheater coil,

means for forcing feed water through the preheater coil, a vaporizing coil connected at both ends to the drum, means for connecting the preheater coil to the vaporizing coil, a connection between the preheater coil and the drum below the normal liquid level therein, a check valve positioned in said means preventing the flow of water thereto into the drum, a casing, a piston dividing said casing into an upper chamber and a lower chamber, an opening in the lower chamber, a valve operable to control said opening, means connecting said valve and the piston, spring pressure means in the casing adapted to normally hold the piston in one position with the valve open, a conduit connecting the upper chamber and the vaporizing coil, and a conduit connecting the lower chamber and the preheater coil.

4. In a continuous coil boiler the combination of a storage drum, a preheater coil, means for forcing feed water through the preheater coil, a vaporizing coil connected at both ends to the drum, means for connecting the preheater coil to the vaporizing coil, a check valve positioned to prevent back flow of water through the preheater coil, a connection between the preheater coil and the drum below the normal liquid level therein, a check valve positioned in said means preventing the flow of water thereto into the drum, a casing, a piston dividing said casing into an upper chamber and a lower chamber, an opening in the lower chamber, a valve operable to control said opening, means connecting said valve and the piston, spring pressure means in the casing adapted to normally hold the piston in a downward position with the valve open,

a conduit connecting the upper chamber and the vaporizing coil, and a conduit connecting the lower chamber and the preheater coil.

5. In a boiler of the semi-flash type the combination of a storage drum, a preheater coil, means for forcing feed water through the preheater coil, a vaporizing coil connected at both ends to the drum, means for connecting the preheater coil to the vaporizing coil including an ejector means operated to circulate water from the drum through the vaporizing coil, a connection between the preheater coil and the drum below the normal liquid level therein, a check valve positioned in said means preventing the flow of water thereto into the drum, a casing, a piston dividing said casing into an upper chamber and a lower chamber, an opening in the lower chamber, a valve operable to control said opening, means connecting said valve and the piston, spring pressure means in the casing adapted to normally hold the piston in a downward position with the valve open, a conduit connecting the upper chamber and the vaporizing coil, and a conduit connecting the lower chamber and the preheater coil.

CHARLES A. FRENCH. 

